The effects of arterial glucose infusion above the celiac axis in the neonatal lamb.

Refractory hypoglycemia has been reported in an infant receiving glucose infusion via an umbilical artery catheter (UAC) above the celiac axis. To prove the hypothesis that hypoglycemia resulted from direct glucose infusion to the pancreas, 15 term spontaneously delivered lambs were infused with 5.3 +/- 0.1 mg X kg-1 min-1 of glucose via an arterial catheter. In 9 glucose was infused below the celiac, and the glucose production rate (GPR) was derived. After a recovery period, the study was repeated with glucose infused above the celiac. During glucose infusion above the celiac, the plasma glucose concentration was lower than when the infusion was given below the celiac (140 +/- 6 vs. 175 +/- 11 mg/dl, p less than 0.01). There was also a fall in the average GPR (3.7 +/- 0.5 vs. 5.5 +/- 0.8 mg X kg-1 min-1, p less than 0.05). In 6 lambs the study was performed in the reverse sequence (high then low infusion) and no differences were noted in the parameters measured. However, there was a marked heterogeneity in the paired GPR in these lambs. We conclude that direct glucose infusion above the celiac increases glucose delivery to the pancreas. This produces increased insulin delivery to the portal system resulting in suppressed GPR and reduction in plasma glucose concentration. These changes may account for refractory hypoglycemia in infants clinically when glucose is infused above the celiac through a UAC.